Golf ball and method of manufacture

Abstract

This invention relates to golf balls having a relatively soft cover and soft core which, in combination, provide golf balls with PGA compression ratings under 70 and a cover Shore D hardness of about 57 or less having good play "feel" and a soft sound.

What is claimed is: 
     
       1. A two-piece golf ball comprising a solid core and a cover layer with a Shore D hardness of 57 or less, the ball having a PGA compression of 62 or less and a coefficient of restitution of at least 0.730. 
     
     
       2. A golf ball according to claim 1, wherein the cover layer has a Shore D hardness of 20-54. 
     
     
       3. A golf ball according to claim 1, wherein the cover layer has a Shore D hardness of 20-50. 
     
     
       4. A golf ball according to claim 1, wherein the ball has a PGA compression of about 60 or less. 
     
     
       5. A golf ball as claimed in claim 1, wherein said ball has a mechanical impedance with a primary minimum value in the frequency range of 2,400 or less Hz when said ball is maintained under conditions of about 21° C., 1 atmosphere of pressure and 50% relative humidity for 15 or more hours immediately prior to frequency testing. 
     
     
       6. A golf ball as claimed in claim 2, wherein said ball has a mechanical impedance with a primary minimum value in the frequency range of 1,800-2,400 Hz. 
     
     
       7. A two-piece golf ball comprising a solid core and a cover layer with a Shore D hardness of 57 or less, the ball having a PGA compression of 62 or less, wherein said cover layer comprises ionomeric resin. 
     
     
       8. A golf ball as claimed in claim 7, wherein said ionomeric resin is acrylate ester containing and is formed from the reaction of the following: an olefin having 2-8 carbon atoms;   an unsaturated monomer of the acrylate ester class having 1-21 carbon atoms; and   an acid which includes at least one member selected from the group consisting of α, β-ethylenically unsaturated mono- or dicarboxylic acids.   
     
     
       9. A golf ball as claimed in claim 8, wherein said cover layer has a Shore D hardness in the range of 20-57 and said ball has a PGA compression in the range of 10-62. 
     
     
       10. A golf ball as claimed in claim 8, wherein said cover layer has a Shore D hardness in the range of 40-57 and said ball has a PGA compression in the range of 20-62. 
     
     
       11. A golf ball as claimed in claim 8, wherein said cover layer has a Shore D hardness in the range of 45-54 and said ball has a PGA compression in the range of 30-60. 
     
     
       12. A golf ball comprising a solid core and a single cover layer, said cover layer having a Shore D hardness of 54 or less, the ball having a PGA compression of 67 or less and a coefficient of restitution of at least 0.730. 
     
     
       13. A golf ball according to claim 12, wherein the cover layer has a Shore D hardness of 20-54. 
     
     
       14. A golf ball according to claim 12, wherein the cover layer has a Shore D hardness of 40-54. 
     
     
       15. A golf ball according to claim 12, wherein the ball has a PGA compression of about 62 or less. 
     
     
       16. A golf ball as claimed in claim 12, wherein said ball has a mechanical impedance with a primary minimum value in the frequency range of 2,400 or less Hz when said ball is maintained under conditions of about 21° C., 1 atmosphere of pressure and 50% relative humidity for 15 or more hours immediately prior to frequency testing. 
     
     
       17. A golf ball as claimed in claim 13, wherein said ball has a mechanical impedance with a primary minimum value in the frequency range of 1,800-2,400 Hz. 
     
     
       18. A golf ball comprising a solid core and a single cover layer, said cover layer having a Shore D hardness of 54 or less, the ball having a PGA compression of 67 or less, wherein said cover layer comprises ionomeric resin. 
     
     
       19. A golf ball as claimed in claim 18, wherein said cover layer has a Shore D hardness in the range of 20-54 and said ball has a PGA compression in the range of 10-67. 
     
     
       20. A golf ball as claimed in claim 18, wherein said cover layer has a Shore D hardness in the range of 40-54 and said ball has a PGA compression in the range of 20-67. 
     
     
       21. A golf ball of two-piece construction comprising a solid core and a single layer cover, the cover having a Shore D hardness of 57 or less, the ball having a mechanical impedance with a primary minimum value in the frequency range of 2400 Hz or less when said ball is maintained under conditions of about 21° C., 1 atmosphere of pressure and 50% relative humidity for 15 or more hours immediately prior to frequency testing. 
     
     
       22. A golf ball as claimed in claim 21, wherein said primary minimum value is in the range of 1800-2400 Hz. 
     
     
       23. A golf ball as claimed in claim 21, wherein said primary minimum value is in the range of 2000-2400 Hz.